The present invention relates to solar energy heaters and more particularly to one which employs a fluidized bed.
A variety of schemes have been devised for increasing the efficiency of heating the air in solar air heaters. Such schemes include the specific focusing of the sun rays onto the solar air heater, design of intricate and complicated heat-absorbing panels disposed within the solar air heater, just to mention but two of such proposals. For a solar air heater, it has been proposed to heat a compressed gas containing minute carbon fines (eg. 600 A in diameter) by solar energy for powering a Brayton cycle gas turbine. The carbon fines are oxidized during the solar energy absorption step and the resulting gas exhausted to the atmosphere from the turbine. (Arlon J. Hunt, Small Paticle Heat Exchanges, Lawrence Berkeley Laboratory, University of California/Berkeley, LBL-7841, June 1978). No heat storage from the carbon fines nor reuse thereof is even remotely proposed. For solar liquid heaters, it even has been proposed to combine the sun focusing effect with high boiling solar-absorbing fluids of critical optical density wherein minute colloidal size particles are suspended within such transparent solar-absorbing liquid (U.S. Pat. No. 4,055,958). The heat that is collected in solar liquid heaters can be stored for later use by simple heat-insulating storage of the heated liquid withdrawn from the solar heater. Storage of the heat from a solar air heater, though, is a more difficult task. Prior proposals in this area, for example, include use of the solar heated air to heat stone or the like for storage of the heat (U.S. Pat. Nos. 3,894,685 and 2,484,127).
The present invention provides a solar air heater which is exceedingly efficient in heating air and which provides a simple and practical method for storing heat from the solar air heater.